After zodiark/hydaelyn, we're going to go on a quest to discover and destroy the thing that threatened the ancients to begin with. In the process, we're going to learn more details about the life of Azem and what she was doing prior to the sundering and we'll probably get some more powerups in the process. It'll turn out that Fandaniel is possessed by that thing but we won't learn that until after we resolve the hydaelyn/zodiark/ arc when we discover that the thing was using Fandaniel to manipulate Zenos into doing its bidding.

That's my completely baseless speculation anyway.